Pipe coupling

ABSTRACT

A pipe coupling for connecting a pipe to a flange associated with another pipe in a sealed manner. The pipe ( 10 ) is formed with circumferential groove ( 10   a ). The coupling comprises a gasket ( 20 ), a mounting ring ( 18 ), and a mounting flange ( 22 ). The ring ( 18 ) is elastically expandable, e.g. by being split, and formed with projecting rib ( 18   a ) adapted to fit into the groove ( 10   a ) and hold the ring affixed to the pipe ( 10 ). The mounting flange ( 22 ) is tightened against both the ring ( 18 ) and a counter-flange ( 12 ), through matching cone-shaped surfaces ( 18   c,    22   a ).

The present patent application is a non-provisional application ofInternational Application No. PCT/IL02/00427, filed May 30, 2002.

FIELD OF THE INVENTION

The present invention relates to pipe couplings of the type adapted tosealingly connect a pipe to a flange of a vessel or the like, or toconnect two ends of pipes extending co-axially one with respect to theother.

BACKGROUND OF THE INVENTION

The most popular pipe coupling presently used for the above purposes isof the type known as hingeable split collar. It comprises a matched pairof half-circular collars hinged to each other at one end and providedwith lugs at the other end. The collars are formed with rims orshoulders adapted to fit into and hold against complementarycircumferential grooves formed near the ends of the pipes. Anelastomeric circular gasket is used, surrounding the space between andpartly extending over the pipe ends. Once the collars are tightened toeach other, by a bolt passing through the respective lugs overlying eachother, the gasket becomes compressed to provide a seal between thepipes.

Pressure admitted into the pipes is effective to enhance the sealingeffect by further pressurizing of the gasket against the rims of thecollars.

These split collar couplings are inherently inconvenient for use,demanding certain manipulation and application of physical force duringthe initial mounting stage.

Other deficiencies of the conventional couplings are that they need tobe made of metal, and hence they are heavy and wasteful in terms ofstorage and transportation space.

It is the prime object of the present invention to provide a pipecoupling of simple, plastic molded integral construction, and allowing awide range of variations satisfying different pipe-work conditions.

It is a further object of the invention to make use of the standardgrooved pipe ends as applied in conjunction with the split collarcouplings.

SUMMARY OF THE INVENTION

Provided according to the invention is a pipe coupling for connecting apipe to a flange associated with another pipe in a sealed manner,wherein the pipe is formed with a circumferential groove the couplingcomprising a gasket, a mounting ring, and a mounting flange,characterized in that the ring is elastically expandable, and formedwith projection means adapted to fit into the groove and hold the ringaffixed to the pipe while the mounting flange is tightened against boththe ring and a counter-flange.

BRIEF DESCRIPTION OF THE DRAWINGS

These and additional constructional features and advantages of theinvention will be more clearly understood in the light of the ensuingdescription of several preferred embodiments thereof, given by way ofexample only with reference to the accompanying drawings, wherein—

FIG. 1 is a cross-sectional view of a pipe coupling featuring thecharacteristics of the present invention as used for connecting a pipeto an outlet/inlet flange of a fluid vessel;

FIG. 2 shows a detail of the coupling of FIG. 1 on an enlarged scale;

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a perspective exploded view of the pipe coupling of FIG. 1;

FIG. 6 is a cross-sectional view of a pipe coupling according to anotherembodiment of the invention used for connecting together a pair ofpipes;

FIG. 7 shows a detail of the coupling of FIG. 6 on an enlarged scale;

FIG. 8 illustrates a modified elastomeric gasket;

FIG. 9 illustrates a modified mounting split ring;

FIG. 10 illustrates a further modification of the mounting split ring;

FIG. 11 is a modification of the ring of FIG. 10;

FIG. 12 is a perspective view of a mounting ring of a hybrid,multi-segment structure;

FIG. 13 is a top view of ring of FIG. 12;

FIG. 14 is a sectional view taken along line XIV-XIV of FIG. 13; and

FIG. 15 shows a mounting split ring worked out of sheet metal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-5, there is shown a pipe 10 coupled to a flange 12by a series of bolts 14. The flange 12 may be welded or otherwise formpart of, for example, a fluid vessel (not shown) via a pipe section 16.

The coupling comprises three parts: a split mounting ring 18; anelastomeric gasket ring 20; and a mounting flange 22.

As more clearly seen in FIGS. 2 and 5, the pipe 10 is formed with acircumferential groove 10 a similar to that used in connection with theconventional hingeable collar couplings.

The split mounting ring 18 is typically made of plastics, and formedwith a circular rib 18 a configured to fit into the groove 10 a.

The rib 18 a is preferably of a generally saw-tooth shape (see FIG. 2),whereby the leading side 18 a′ thereof exactly matches the right angledside wall of the groove 10 a while at the opposite side 18 a″ it isbeveled as shown, for a reason to be explained further below.

The ring 18 is further formed with a circular recess 18 b for snuglyreceiving gasket 20.

The outer contour of the ring 18 has a cone-shape surface 18 c,preferably between 15° and 30°, merging with an upright shoulder 18 d.

Finally, the ring 18 is split by a cut 18 e, for enabling the spreadingor expansion thereof to an extent allowing it to be forced over the openside of the pipe 10 and pushed further until the rib 18 a clicks intothe groove 10 a.

The gasket 20, usually of rubber or other suitable elastomeric material,is preferably formed with an inner slot 20 a for its expansion under thepressure of the flowing through liquid as known in the art (“hydraulicseal”).

The mounting flange 22 has an inner cone-shaped surface 22 a of the sameinclination and length as of the surface 18 c of the ring 18, so thatwhen the bolts 14 are tightened, a firm grip around the ring 18 isachieved along with an axially directed force component acting againstthe shoulder 18 d, as requested for sealing the gasket 20 against theface of the flange 12 in the assembled position of the coupling.

The flange 22, with bores 22 b for the bolts 14, is preferably formedwith arcuate projections 22 c compensating the width of the shoulder 18c.

The manner of assembling the coupling is self-evident in view of theforegoing description. As seen in FIG. 5, the flange 22 is first placedover the pipe 10. Then the mounting split ring 18 is forcibly dressedover the end of the pipe, which is facilitated by the elastic expansionassisted by the beveled portion 18 a″ of the rib 18 a.

Once properly seated over the pipe 10, namely that the rib 18 a gripsaround the groove (10 a), the gasket 20 is placed into the recess 18 b,and the flange 22 is dragged over the ring 18 in the direction of theflange 12 to which it is intended to be fastened.

The counter-force requested to withstand the tightening of the flanges12 and 22 to each other using the bolts 14, thereby squeezing of thegasket 20 to a proper amount, is offered by the rib 18 a trapped withinthe groove 10 a, or, more accurately, the abutment of the portion 18 a′against the upright wall of the groove 10 a.

The coupling substantially as so far described is readily useful forconnecting two pipes of equal (or even unequal) diameters, as depictedin FIGS. 6 and 7, where similar reference numerals are used to denotealready identified parts and components. As illustrated pipe 110includes circumferential grooves 110 a and 210 a. Bolts 114 and 214 forma grip around the ring 118 when tightened.

As clearly seen, two couplings are employed, in a “face-to-face”engaging relationship. Hence, the left-hand side pipe 110 is assembledwith mounting split ring 118, gasket 120 and mounting flange 122, whichis tightened to flange 222, surrounding split ring 218 and gasket 220(rather than to the fixed flange 12 as in the previous embodiment).Thus, the pipe 110 becomes sealingly connected to the pipe 210.

Several modified embodiments will be now described, demonstrating theversatility and other advantages of the present invention.

Referring to FIG. 8, there is exemplified a gasket 320 provided with athin flap or tongue 320 b designed to be inserted into slot 318 e of thesplit ring 318. The positioning of the flap between the ring sectionswill add some flexibility that will compensate for any deviation ofmeasurement or surface irregularities between the ring and thesurrounding mounting flange (not shown), allowing less stringenttolerance control during production.

The mounting split ring 418 of FIG. 9 is formed with a cut-through slot418 e extending at an angle with respect to axial direction.

Rather than employing a split ring, it is possible to have it composedof more than one segment (two segments in ring 518 in FIG. 10 and threein ring 618 in FIG. 11), held together by a rubber band (524 and 624,respectively).

The mounting ring 718 of FIGS. 12-14 is again of a modified design. Aseries of metal inserts 726 are positioned between the segments. Anelastic band 728 is threaded through all segments and inserts enablingthe expansion of the ring 718 as requested for the mounting thereof overa pipe (not shown). The inserts conform the shape of the mounting ringas dictated for its use, namely with teeth 718 a (replacing thecontinuous rib 18 a of FIG. 1) and the cone-shaped outer surface 718 c.

The hybrid or composite structure of the ring 718 offers enhanced firmgrip of the ring against the grooved pipe (not shown), as well aselectrical short-cut between coupled pipes in case such is demanded.

The mounting ring 818 of FIG. 15 is produced not by plastic molding, butof sheet metal processed by known technologies (rolling) to the finalshape. It will be noted that the continuous cone-shaped surface (denoted18 c in FIG. 2) is divided into two: portion 818 c′ and portion 818 c″which together suitably support the inner cone-shaped surface of themounting flange (not shown).

Those skilled in the art to which this invention pertains will readilyappreciate that numerous changes, variations and modifications can beeffectuated without departing from the true spirit and scope of theinvention as defined in and by the appended claims.

1. A pipe coupling comprising: a single gasket, a resilient mountingring made of a flexible material and having a split and a circularrecess in said resilient mounting ring for receiving the gasket, and amounting flange having a cone shaped inner surface, wherein the mountingring is elastically expandable and is integrally formed with an outercone-shaped surface, said outer cone-shaped surface complementary tosaid cone shaped inner surface, and with an inner rib, wherein the ribfits into a circumferential groove formed in a first pipe uponelastically expanding the ring over the first pipe to hold the ringaffixed to the first pipe, wherein the pipe coupling connects the firstpipe to a counter-flange associated with a second pipe in a sealedmanner when the ring is tightened towards the counter-flange, wherebysaid single gasket abuts said first pipe and abuts said resilientmounting ring in use.
 2. The pipe coupling as claimed in claim 1 whereinthe ring is split by a cut extending in an axial plane thereof.
 3. Thepipe coupling as claimed in claim 1 wherein the ring is split by a cutextending in a non-axial plane thereof.
 4. The pipe coupling as claimedin claim 1 wherein the ring is made of plastic material.
 5. The pipecoupling as claimed in claim 1 wherein the inner rib comprises acircular rib.
 6. The pipe coupling as claimed in claim 5 wherein the ribis of a generally saw-tooth shape having a right-angled side and abeveled side.
 7. The pipe coupling as claimed in claim 1 wherein thegasket is elastomeric.
 8. The pipe coupling as claimed in claim 7wherein the gasket is formed with an inner slot.
 9. The pipe coupling asclaimed in claim 8 wherein the gasket is formed with a thin flap. 10.The pipe coupling as claimed in claim 1 wherein the cone angle isbetween 150-300 degrees relative to the axis of the ring.
 11. The pipecoupling as claimed in claim 10 wherein an upright shoulder extendsaround the end of the outer cone-shaped surface.
 12. The pipe couplingas claimed in claim 1 wherein the mounting flange is formed with aseries of bores through which tightening bolts are adapted to pass. 13.The pipe coupling as claimed in claim 12 wherein the series of bores arepartly surrounded by arcuate projections.
 14. The pipe coupling asclaimed in claim 1 wherein the ring is composed of more than onesegment, the segments being held together by an elastic band.
 15. Thepipe coupling as claimed in claim 14 wherein metal inserts areinterposed between adjacent segments.
 16. The pipe coupling as claimedin claim 15 wherein the segments and inserts are held together by theelastic band threaded therethrough.
 17. The pipe coupling as claimed inclaim 1 wherein the ring is made of sheet metal.